Country star Keith Urban has admitted his treatment for alcohol addiction was a bigger challenge than he expected.

The singer, who is married to Nicole Kidman, said on his website the timing of his rehab was "far from ideal" but that life had become "unmanageable".

He had expected to stay for 30 days but found not drinking was only part of the solution and stayed for three months.

Urban, 39, thanked fans for their support and also confirmed three tour dates in the UK in April.

He also paid tribute to the support of his wife and family and said he was looking forward to touring again.

"Learning about abstinence was one thing, but then there was all this other area of my life to start learning about," he said.

"And so 30 days became 60, and 60 days became 90, and with each week that passed I found myself really learning how to surrender."

While in the clinic he missed the release of his latest album, Love, Pain and the Whole Crazy Thing, and was not present to accept his second male vocalist of the year honour at the Country Music Association Awards.

"There was no big cataclysmic event that happened right before I went in," he added.

"It was a lot of small things that were happening in my life, a lot of small moments that were starting to accumulate that were telling me very loud and clear that I was a long way from my program of recovery, and they were making my life unmanageable."